Cretaceous petroleum system elements in the Komombo Basin, Egypt

Abstract

The petroleum system elements in the Komombo Basin have not yet been fully assessed. This study aims to evaluate source rocks, reservoirs, and seals within the basin by integrating 2D seismic profiles, and well logs together with geochemical, core, and petrophysical data. Four source rocks are identified within the Cretaceous shale intervals of the B member of the Six Hills, upper Maghrabi, Quseir, and Dakhla formations. The quality of the B member, upper Maghrabi, and Quseir source rocks is good to very good, while the Dakhla Formation demonstrates good to excellent quality. Geochemical characteristics vary across the basin, with higher kerogen quality and thermal maturity observed in the depocenter compared to the flanks. Four reservoirs are recognized in the basin, including the A member, C member, sandstones within D-G members of the Six Hills, and Sabaya-Maghrabi formations. The A member reservoir demonstrates moderate reservoir quality, while the C member reservoir displays fair quality. Numerous sandstones with 15-25% porosity values are observed within the D-G members. The Sabaya-Maghrabi reservoir generally exhibits good to very good quality and is characterized by high porosity and varying permeability. Due to their high organic matter content, the Dakhla and Quseir formations show potential as unconventional reservoirs. Several shale units within the Komombo Basin serve as potential seal rocks. These include the B member of the Six Hills, Abu Ballas, upper Maghrabi, and Taref formations, as well as intra-formational shales within the reservoir rocks. Seismic interpretation indicates faults are the predominant trapping mechanism in the basin.